[Easy operation] This water electrolyzer is easy to operate. Install the iron and aluminum bars, place them into the water to be tested, plug in the device and turn on the switch. After a short period, turn off the power switch to view the testing result. [Working principle] The water electrolyzer applies an electric field in water using two electrodes (iron and aluminum rods). When powered, positive ions are released from the iron rod and react with negatively charged ions in the water, forming insoluble metal clusters. These clusters coalesce and adsorb colloidal, organic, and inorganic substances present in the water. [Working principle] Due to the electric current, metal particles dissolved in water—such as lead, chromium, manganese, potassium, cobalt, etc.—are reduced and gradually aggregate into visible metal clusters. Color changes occur due to the different reactions of various metal ions. [Note] After turning on the power, do not touch the electrodes or place fingers in the test water. Keep the device away from children. After use, dry the electrodes with a clean, dry cloth and wipe the iron rod with fine gauze before storing properly. Plug Type: US Plug, compatible with countries including Canada, India, Mexico, Thailand, Taiwan, and the Philippines. Voltage: AC 110V Color: As shown Material: Plastic + Metal Package Contents: 1 x Water Quality Tester Only the above items are included; other products are not included. Note: Lighting reflections and differences in display screens may cause slight variations in color between the image and the actual item. Measurement error allowance is +/- 1-3 cm.